82 
CLEARNESS OF T11E ATJIOSrilERS. 
the atmosphere. Notwithstanding the great distance, we 
could distinguish not only the houses, the sails of the ves- 
sels, and the trunks of the trees, but we could discern the 
vivid colouring of the vegetation of the plains. These phe- 
nomena are owing not only to the height of the site, hut 
to the pecidinr modifications of the air in warm climates. 
In every zone, an object placed on a level with the sea, 
and viewed in a horizontal direction, appears less luminous, 
than when seen from the top of a mountain, where vapours 
arrive after passing through strata of air of decreasing 
density. Differences equally striking are produced by the 
influence of climate. The surface of a lake or large river is 
less resplendent, when we sec it at an equal distance, from 
the top of the higher Alps of Switzerland, than when we 
view it from the summit of the Cordilleras of Peru or ot 
Mexico. In proportion as the air is pure and serene, the 
solution of the vapours becomes more complete, and the light 
loses less in its passage. When from the shores of the Pacific 
we ascend the elevated plain ot Quito, or that ot Antisana, 
we are struck for some days by the nearness at which we 
imagine we see objects which are actually seven or eight 
leagues distant. The peak of Teyde has not the advantage 
of being situated in the equinoctial region ; hut the dryness 
of the columns of air which rise perpetually above the neigh- 
bouring plains of Africa, and which the eastern winds convey 
with rapidity, gives to the atmosphere of the Canary Islands 
a transparency which not only surpasses that ot the air o. 
Naples and Sicily, but perhaps exceeds the purity of the 
skv of Quito aiid Peru. This transparency may be re- 
garded as one of the chief causes of the beauty ol landscape 
scenery in the torrid zone ; it heightens the splendour of 
the vegetable colouring, and contributes to the magical 
effect of its harmonies and contrasts. If the mass of 
light, which circulates about objects, fatigues the external 
senses during a part of the day, the inhabitant of the 
southern climates has his compensation in moral enjoy- 
ment. A lucid clearness in the conceptions, and a serenity 
of mind, correspond with the transparency of the surround- 
inrr atmosphere. AVe feel these impressions without going 
beyond the boundaries of Europe. 1 appeal to travellers 
wlio have visited countries rendered famous by the great 
